Quoting Thomas Huth (2023-07-14 10:30:33) > On 14/07/2023 10.21, Nico Boehr wrote: > > Quoting Thomas Huth (2023-07-13 10:21:12) > >> On 13/07/2023 10.17, Claudio Imbrenda wrote: > >>> On Thu, 13 Jul 2023 09:28:19 +0200 > >>> Thomas Huth <thuth@xxxxxxxxxx> wrote: > >>> > >>> [...] > >>> > >>>>> + irq_set_dat_mode(IRQ_DAT_ON, AS_PRIM); > >>>>> + psw_mask_clear_bits(PSW_MASK_HOME); > >>>>> + > >>>>> + /* restore the old CR 13 */ > >>>>> + lctlg(13, old_cr13); > >>>> > >>>> Wouldn't it be better to always switch to HOME address mode directly in our > >>>> startup code already (where we enable DAT)? Switching back and forth every > >>>> time we enter SIE looks confusing to me ... or is there a reason why we > >>>> should continue to run in primary address mode by default and only switch to > >>>> home mode here? > >>> > >>> the existing tests are written with the assumption that they are > >>> running in primary mode. > >>> > >>> switching back and forth might be confusing, but avoids having to > >>> fix all the tests > >> > >> Which tests are breaking? And why? And how much effort would it be to fix them? > > > > Since you're not the first asking this, I took the time and > > moved^Whacked everything to home space mode: > > > > - all SIE-related tests time out, even when we load CR1 properly before SIE > > entry. Most likely just an oversight and fixable. > > - the skey test encounters an unexpected PGM int with a weird backtrace > > where I couldn't easily figure out what goes wrong > > - edat test fails with a similar looking backtrace > > > > All in all, it is probably fixable, but additional effort. > > > > I think explicitly switching the address space mode gives us additional > > flexibility, since sie() doesn't need to make assumptions about which address > > space we're running in. > > Ok, thanks for checking. Then let's go with this patch here for now, but > maybe you could add a more detailed comment in the source code that talks > about the reasons for switching each time instead of only once during startup? OK, how about this? * Set up home address space to match primary space. Instead of running * in home space all the time, we switch every time in sie() because: * - tests that depend on running in primary space mode don't need to be * touched * - it avoids regressions in tests * - switching every time makes it easier to extend this in the future, * for example to allow tests to run in whatever space they want
